Well the Antec 1200 doesn't have a hole in the bottom for the fan, so it's just taking air from right inside the case. Basically, the PSU sit's on rubber feet, which give it about 1.5cm of space to suck air through.
Here's a pic of the bottom of a 1200.

Well the Antec 1200 doesn't have a hole in the bottom for the fan, so it's just taking air from right inside the case. Basically, the PSU sit's on rubber feet, which give it about 1.5cm of space to suck air through.
Here's a pic of the bottom of a 1200.